JetQi
=========

This is a modified Qi bootloader for the Samsung Jét smartphone. It can 
boot from the external SD card. JetQi is based on SmartQi by Roberto Gordo 
Saez <[email protected]> (git://gitorious.org/qi-smartq/smartqi.git).

Use make to compile. The resulting binary file will be placed on
image/qi-s3c6410-<version>-JetQi. Look at the script install-smartq-qi.sh
in order to make a bootable SD card.

-- Dopi <[email protected]>


Qi
==

Qi (named by Alan Cox on Openmoko kernel list) is a minimal bootloader that
"breathes life" into Linux.  Its goal is to stay close to the minimum needed
to "load" and then "boot" Linux -- no boot menus, additional peripheral init
or private states.


What's wrong with U-Boot, they keep telling people to not reinvent the wheel?
=============================================================================

U-Boot is gradually becoming a simplified knockoff of Linux.  After using it a
while, it became clear we were cutting and pasting drivers into U-Boot from
Linux, cutting them down and not having a plan to maintain the U-Boot versions
as the Linux ones were changed.

We decided that we would use full Linux for things that Linux is good at and
only have the bootloader do the device init that is absolutely required before
Linux can be pulled into memory and started.  In practice since we had a working
U-Boot implementation it meant cutting that right down to the bone (start.S
mainly for s3c2442) and then building it up from scratch optimized to just do
load and boot.


Samsung - specific boot sequence
================================

Right now Qi supports Samsung "steppingstone" scheme devices, but in fact it's
the same in processors like iMX31 that there is a small area of SRAM that is
prepped with NAND content via ROM on the device.  There's nothing that stops Qi
use on processors without steppingstone, although the ATAG stuff assumes we deal
with ARM based processor.


Appending to commandline
========================

You can append to the Qi commandline by creating a file /boot/append-<device>,
eg, /boot/append-GTA02 containing the additional kernel commandline you want.

This means you can affect the boot per-rootfs, but that if you reimage the
rootfs you at the same time define what is appeneded.  Because these files are
looked for with the <device> name in them, options can be selected depending on
the device the rootfs is run on.


Initrd support
==============

Initrd or initramfs in separate file is supported to be loaded at given
memory address in addition to kernel image.  The ATAGs are issued accordingly.